Sound diffusion systems - Frequency response

This consists in a diagram which displays the accurateness with which all the frequencies of the audible band are reproduced. The following diagram is an example:

Frequency response of a diffuser

Here sensitivity is displayed in relation to frequency. This in theory should always remain constant so that the diffuser can have the same response at all frequencies. The diagram also shows the amplitudes measured at different angles in relation to the direction of the diffusion of sound. As we can see, at a 90 degree angle, the response differs greatly to that at 0 degrees, especially at high frequencies, which as we know, are those which are most affected by direction.